Semi-spherical cover forming die and method

Abstract

The invention provides a semi-spherical cover forming die. The semi-spherical cover forming die comprises an upper die and a lower die which move relatively through a guide mechanism. Wherein the upper die and the lower die can be used for forming a spherical body part of a semi-spherical cover at one time, pressing a curved surface type surface outside the spherical body, and simultaneously forming an upward flanging on the rear side of a part; meanwhile, the invention further provides a semi-spherical cover forming method. When a part is formed by adopting the mold structure, the spherical body part of a semi-spherical cover can be formed at one time, a curved surface type surface outside the spherical body can be pressed out, meanwhile, an upward turned edge on the rear side of the part can be formed, and the part forming process of three working procedures is simplified into one working procedure.

Description

Technical Field

[0001] The present application belongs to the field of stamping die technology, and in particular, relates to a semi-spherical cover forming die and method. Background Art

[0002] Among various stamping methods of sheet metal, deep drawing is a very important forming method. This is because the sheet metal stamping process has a high forming efficiency and can be widely used in mass production processes, which not only saves production costs but also greatly improves production efficiency. It has been widely used in aerospace, household appliances, instrumentation, electronic communications, ships, automobiles and other industries.

[0003] The shapes of deep drawn parts are diverse. According to the processability of deep drawn parts, they are divided into the following types: straight wall axisymmetric, straight wall non-axisymmetric, curved surface axisymmetric, and curved surface non-axisymmetric. The forces on each part of the blank, the deformation characteristics of the blank, the failure form, etc. during the deep drawing process of parts of different shapes are different, and the corresponding forming limits of the blank and the design of the mold are also different. The forming characteristics, failure forms, and failure locations of deep drawn parts of different shapes are more obvious in the deep drawing of curved parts than in the deep drawing of straight wall parts. This is because the force conditions on the side walls of curved parts during the deep drawing process are more complicated than those on straight wall parts. Spherical parts are curved axisymmetric parts. During the deep drawing process, except for the flange part and the deep drawing of cylindrical parts, there are also some other problems.

[0004] In addition to the same deformation during forming, the middle part of the spherical part also undergoes deformation, that is to say, the edge and middle part of the blank are both deformation zones, so deep drawing of spherical parts is more difficult. Summary of the invention

[0005] Purpose of the invention: In order to ensure the processing quality of parts and improve efficiency, the present invention provides a molding method and mold structure for a semi-spherical cover part.

[0006] In a first aspect, the present application provides a semi-spherical cover forming mold, the mold comprising an upper mold and a lower mold that move relative to each other through a guide mechanism;

[0007] The upper die and the lower die can form the spherical body part of the semi-spherical cover at one time, and press out the curved surface outside the spherical body, and can also form the upward flange on the rear side of the part.

[0008] Preferably, the upper die is composed of an upper die plate, a first pad, a concave die, a guide part and a standard fastener;

[0009] Among them, the upper template is at the top, a first pad is arranged under the upper template, a concave mold is arranged under the first pad, and guide parts are arranged at both ends of the upper template.

[0010] Preferably, when working, the upper die is fixed to the upper platform of the stamping equipment by a special die handle and a pressure plate. The entire upper die is regarded as a whole, which moves up and down with the upper platform of the punch press. After moving downward until it contacts the lower die body, it can exert huge pressure on the product parts.

[0011] Preferably, the lower die is composed of a punch, a pressure ring, a die frame, an outer frame, a first guide block, a second guide block, a first positioning key, a second positioning key, a flanging punch, a lower die plate, a second pad, a first guide column, a second guide column, a washer and other standard fasteners;

[0012] Among them, the part at the top middle position of the lower mold that fits with the inner surface of the semi-spherical cover part is the punch, and the front, left and right sides of the punch are surrounded by a pressure ring, and the pressure ring and the contact surface of the punch maintain a sliding fit. Behind the punch and the pressure ring is the flanging punch, and the pressure ring and the contact surface of the punch and the flanging punch also maintain a sliding fit. The periphery of the punch, the pressure ring and the flanging punch is the mold frame, and the first guide block and the second guide block are installed in the vertical direction in front of the mold frame.

[0013] Preferably, the first guide block and the second guide block are higher than the mold frame by a certain height. The outside of the mold frame is an outer frame, and the first positioning key and the second positioning key close to the front and rear sides of the mold frame are installed on the outer frame. Under the outer frame is a pad, under the pad is the lower template, and under the lower template is a pad. Each plate is fixed together with screws and pins to form a whole. At the same time, four hitting rods are installed between the pressure ring and the pad. The hitting rods pass through the pad and the lower template, and a certain length is exposed under the lower template.

[0014] Preferably, during operation, the lower die is entirely fixed on the lower platform surface of the stamping equipment through a pressing plate tool.

[0015] In a second aspect, the present application also provides a method for forming a semi-spherical cover, the method comprising:

[0016] Step 1: Install the upper die part of the mold on the upper platform of the punch press, and install the lower die part of the mold on the lower platform of the punch press, so that the upper and lower dies are fixed reliably;

[0017] Step 2: Use the ejector device in the lower platform of the equipment and the ejector rod of the mold to lift the blank holder ring until the upper molding surface of the blank holder ring is higher than the convex mold surface, and prepare for material discharge;

[0018] Step 3: Place the flat blank on the upper plane of the blank holder and align it;

[0019] Step 4: Start the stamping equipment to press the upper die part downward. The C surface of the concave die in the upper die contacts the part first, and works together with the G surface of the blank holder to press the front, left and right surfaces of the upper surface of the blank. The blank in this area is the material outside the residual amount of the semi-spherical cover part of the product.

[0020] Step 5: As the die continues to move downward, the concave mold surface B and the blank holder surface F work together to press the 10mm margin area on the edge of the semi-spherical cover part of the product. Since the material in this area is close to the forming area, the blank material in this area will flow;

[0021] Step 6: As the concave die in the upper mold moves downward again, the semi-spherical surface D of the convex die in the blank holder contacts the blank, gradually forming a semi-spherical surface of the product;

[0022] Step 7, the die continues to move downward until the die completely presses the blank holder to the lowest position, completing the forming process of the semi-spherical cover; at the same time, the flange punch completes the forming of the upward side flange of the semi-spherical cover part;

[0023] Step 8: The upper mold moves upward to take out the part, completing the molding of the part.

[0024] Preferably, the method further comprises:

[0025] While step 7 is being carried out, the flanging punch located behind the punch and the blank holder lifts up the blank on the rear side.

[0026] Beneficial technical effects of this application:

[0027] The mold structure is used to form parts, which can form the spherical body part of the semi-spherical cover at one time, and press out the curved surface outside the spherical body. At the same time, the upward flange of the rear side of the part can also be formed, and the three-step part forming process is simplified into one step, which greatly simplifies the processing process, saves labor time costs, shortens the production cycle, and improves processing efficiency; the quality of the parts is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a top view of the mold provided in an embodiment of the present application;

[0029] Figure 2 is a cross-sectional view taken along line AA provided in an embodiment of the present application;

[0030] Figure 3 It is a longitudinal cross-sectional view taken along line BB provided in an embodiment of the present application;

[0031] Figure 4 It is a 3D exploded view of the mold provided in the embodiment of the present application;

[0032] Figure 5 It is an axonometric view of the punch of the main working parts provided in the embodiment of the present application;

[0033] Figure 6 This is an axonometric view of the profile of the blank holder ring, a main working part provided in an embodiment of the present application;

[0034] Figure 7 It is an axonometric view of the concave model surface of the main working parts provided in the embodiment of the present application;

[0035] Figure 8 is a top view of a mold frame notch provided in an embodiment of the present application;

[0036] Fig. 9 This is a front view of a finished part of a semi-spherical cover provided in an embodiment of the present application;

[0037] Fig.10 This is a front view of a finished part of a semi-spherical cover provided in an embodiment of the present application;

[0038] Fig.11 It is a three-dimensional axonometric diagram of a finished part of a semi-spherical cover provided in an embodiment of the present application;

[0039] Among them, 1-punch, 2-pressure ring, 3-mold frame, 4-outer frame, 5-die, 6-first guide block, 7-second guide block, 8-flanging punch, 9-first positioning key, 10-second positioning key, 11-first pad, 12-upper template, 13-second pad, 14-lower template, 15-hitting rod, 16-pad one, 17-pad two, 18-first guide sleeve, 19-second guide sleeve, 20-first guide column, 21-second guide column. DETAILED DESCRIPTION

[0040] See also Figure 1-Figure 11 The molding die of the semi-spherical cover part provided by the present application comprises an upper die and a lower die which can move relative to each other through a guide mechanism. Figure 4 The exploded diagram is used as a basic perspective to explain the invention in detail.

[0041] The upper die is composed of an upper die plate, a first pad, a concave die, guide parts and standard fasteners. The upper die plate is on the top, and there is a first pad under the upper die plate. The concave die is installed under the first pad, and guide parts are installed at both ends of the upper die plate. The parts of the upper die are fixed by screws and pins to form a whole. When working, the upper die is fixed to the upper platform of the stamping equipment (punch press) by a special die handle and a pressure plate. The entire upper die can be regarded as a whole, which can move up and down with the upper platform of the punch press. After moving downward until it contacts the lower die body, it can exert huge pressure on the product parts.

[0042] The lower die is composed of a punch, a pressure ring, a die frame, an outer frame, a first guide block, a second guide block, a first positioning key, a second positioning key, a flanging punch, a lower die plate, a second pad, a first guide column, a second guide column, a washer and other standard fasteners. The part in the middle of the uppermost part of the lower die that fits the inner surface of the semi-spherical cover part is the punch. The front, left and right sides of the punch are surrounded by the blank holder. The blank holder and the contact surface of the punch maintain sliding cooperation. The punch and the blank holder are behind the flange punch. The contact surfaces of the blank holder and the punch and the flange punch also maintain sliding cooperation. The periphery of the punch, the blank holder and the flange punch is the die frame. The first guide block and the second guide block are installed in the vertical direction in front of the die frame. The first guide block and the second guide block are higher than the die frame by a certain height. The outside of the die frame is the outer frame. The first positioning key and the second positioning key that are close to the front and rear sides of the die frame are installed on the outer frame. Under the outer frame is the pad, under the pad is the lower template, and under the lower template is the pad. Each plate is fixed together by screws and pins to form a whole. At the same time, 4 hitting rods are installed between the blank holder and the pad. The hitting rod passes through the pad and the lower template and exposes a certain length under the lower template. When working, the lower die is fixed on the lower platform surface of the stamping equipment by the pressing plate tool.

[0043] See the accompanying drawings, Figures 1 to 8 , further explain the structure and special functions of key parts in this mold structure.

[0044] The bottom surface of the die 5 has a profile A that completely covers the outer surface of the semi-spherical part and a curved surface B outside the spherical surface. A step profile C is also made in the area outside the part profile. Profile A and profile B cover the outer shape of the semi-spherical cover part with a certain margin. The step profile C is complementary to the profile G of the pressure ring, and there is no gap after closing.

[0045] The punch 1 is characterized in that it has a semi-spherical structural profile D which is completely fitted with the inner profile of the semi-spherical cover part, the gap between the profile D and the concave model surface A is the material thickness of a part, and the four walls of the side of the punch are smooth.

[0046] The pressure ring 2 has an opening H at the rear, and the three surfaces of the opening H are in sliding cooperation with the front, left and right side surfaces of the punch.

[0047] The pressure ring 2 has a profile E on it which contacts the inner profile of the curved surface outside the hemispherical shape of the hemispherical cover part. The gap between profile E and the concave model surface B is the material thickness of a part. Profile E and concave model surface B work together to ensure the molding quality of the curved surface part of the hemispherical cover.

[0048] The pressure ring 2 has a thickened step surface F on its upper surface outside the range of the hemispherical cover part surface. The gap between the step surface F area and the die surface B is 0 mm. This area is the stretching transition zone of the hemispherical part. The 0 gap strictly restricts the material flow near the edge of the part.

[0049] The blank holder 2 has a step area profile G on it, which is 0.5mm higher than the profile F. At the outermost side of the semi-spherical cover part, the gap between the remaining concave model surfaces C is 0mm, and its function is to completely restrict the flow of the part material.

[0050] The flanging punch 8 is located behind the punch and the pressure ring, fits with the back of the punch and the pressure ring, is vertically fixed between the mold frames by means of a slot connection, and is in a sliding cooperation relationship with the pressure ring during movement.

[0051] The mold frame 3 is located outside the punch and the pressure ring. Its height and shape are consistent with the pressure ring and the punch. There is a specially shaped groove A at the back, which provides a vertical fixed socket for the flanging punch. There are also two square openings on both sides of the groove A to limit the position of the flanging punch.

[0052] The mold frame 3 also has a groove B and a groove C on the front, which provide fixed positions for the first guide block 6 and the second positioning block 7 respectively, so that the guide blocks keep the same position.

[0053] The outer frame 4 is located outside the mold frame, preventing the vertical flanging punch from tilting due to outward extrusion during operation, and at the same time enhancing the stability of the spatial position of the first guide block and the second guide block.

[0054] The first guide block 6 and the second guide block 7 are characterized in that they are vertically fixed in the mold frame 3, and the contact surfaces of the two blocks and the blank holder are kept on the same plane, and maintain a sliding fit relationship with the blank holder when in motion.

[0055] The first positioning key 9 and the second positioning key 10 are characterized in that they are fixed on the upper plane of the outer frame, and their sides are close to the side of the mold frame that is higher than the outer frame, which further strengthens the structural performance of the mold frame.

[0056] The second pad 11 is a plate-like structure with high hardness and impact resistance. It is located between the die and the upper mold plate. When the mold is working, it bears and disperses the impact force of the die on the upper mold plate to protect the upper mold plate.

[0057] The second pad 13 is a plate-like structure with high hardness and impact resistance. It is located below the outer frame and above the lower template. Its middle upper plane contacts the blank holder and the punch. When the mold is working, it bears and disperses the impact force of the punch on the lower template to protect the lower template.

[0058] In other embodiments of the present application, a molding method and mold structure of a hemispherical cover part includes an upper mold and a lower mold. The upper mold part includes: a template, a pad, a concave mold and a guide part. The lower mold includes: a punch, a pressure ring, a mold frame, an outer frame, a first guide block, a second guide block, a first positioning key, a second positioning key, a flanging punch, a lower template, a second pad, a guide part, a washer and other standard fasteners.

[0059] The dimensions of the working parts such as the punch, die, blank holder and flanging punch should match the dimensions of the product parts, and should be made of high hardness and high wear-resistant cold working die steel. Materials such as Cr12MoV, Cr12, YG15, YG8 can be selected and hardened as required.

[0060] The appearance of positioning parts such as mold frame, outer frame, guide block, positioning key, etc. should meet the use requirements and achieve the predetermined functions. The manufacturing material can be selected from 45# steel with general hardness.

[0061] Description: The plate-shaped parts such as the upper template, the lower template, the pad and the like are made of ordinary steel.

[0062] It is stated that guiding parts and fastening parts should be selected according to national and industry standards.

[0063] As described above, the first pad and the second pad plate-shaped parts as parts that indirectly bear the impact force should be made of materials with higher hardness, such as T8A 45, etc., and should be quenched before use to increase the hardness.

[0064] In other embodiments of the present application, the present invention further provides a method for using a semi-spherical cover forming mold. The forming process of the part is mainly divided into the following steps:

[0065] Step 1: Install the upper die part of the mold on the upper platform of the punch press, and install the lower die part of the mold on the lower platform of the punch press to ensure that the upper and lower dies are fixed reliably.

[0066] Step 2: Use the ejector device in the lower platform of the equipment and the mold ejector rod to lift the blank holder ring until the upper mold surface of the blank holder ring is higher than the convex mold surface, and prepare for material discharge.

[0067] Step 3: Place the flat blank on the plane of the blank holder and align it. If the blank is not placed stably, press the blank to make it consistent with the shape of the blank holder. Align the blank again to ensure that there is enough blank holder allowance outside the theoretical shape of the part.

[0068] Step 4: Place the flat blank on the plane of the blank holder and align it. If the blank is not placed stably, press it gently to make it in the same direction as the blank holder surface, and align the blank again to ensure that there is enough blank holder allowance outside the theoretical shape of the part.

[0069] Step 5: After the operator keeps a safe distance from the equipment, start the stamping equipment to press the upper die part downward. The C surface of the concave die in the upper die first contacts the part and works together with the G surface of the blank holder to press the front, left and right sides of the upper surface of the blank. The blank in this area is the material outside the excess of the semi-spherical cover part of the product.

[0070] Step 6: As the die continues to move downward, the concave surface B and the blank holder surface F work together

[0071] Press the 10mm margin area on the edge of the semi-spherical cover part of the product. Since the material in this area is close to the forming area, material flow will occur in this area.

[0072] Step 7: As the concave die in the upper mold moves downward again, the semi-spherical surface D of the punch in the blank holder contacts the blank, gradually forming the semi-spherical surface of the product.

[0073] Step 8: While step 7 is in progress, the flanging punch located behind the punch and the blank holder lifts up the blank on the rear side.

[0074] Step 9: The die continues to move downward until the die completely presses the blank holder to the lowest position, completing the forming process of the semi-spherical cover. At the same time, the flange punch completes the forming of the upward side flange of the semi-spherical cover part.

[0075] Step 10: The upper mold moves upward, takes out the part, and completes the molding of the part.

Claims

1. A semi-spherical cover forming mold, characterized in that: The mold comprises an upper mold and a lower mold that move relative to each other through a guide mechanism; The upper die and the lower die can form the spherical body part of the semi-spherical cover at one time, and press out the curved surface outside the spherical body, and can also form the upward flange on the rear side of the part.

2. The mold according to claim 1, characterized in that: The upper die is composed of an upper die plate, a first pad, a concave die, guide parts and standard fasteners; Among them, the upper template is at the top, a first pad is arranged under the upper template, a concave mold is arranged under the first pad, and guide parts are arranged at both ends of the upper template.

3. The mold according to claim 2, characterized in that: During operation, the upper die is fixed to the upper platform of the stamping equipment through a special die handle and a pressure plate. The entire upper die is regarded as a whole, and moves up and down with the upper platform of the punch press. After moving downward until it contacts the lower die body, it can exert huge pressure on the product parts.

4. The mold according to claim 3, characterized in that: The lower die is composed of a punch, a pressure ring, a die frame, an outer frame, a first guide block, a second guide block, a first positioning key, a second positioning key, a flanging punch, a lower die plate, a second pad, a first guide column, a second guide column, a washer and other standard fasteners; Among them, the part at the top middle position of the lower mold that fits with the inner surface of the semi-spherical cover part is the punch, and the front, left and right sides of the punch are surrounded by a pressure ring, and the pressure ring and the contact surface of the punch maintain a sliding fit. Behind the punch and the pressure ring is the flanging punch, and the pressure ring and the contact surface of the punch and the flanging punch also maintain a sliding fit. The periphery of the punch, the pressure ring and the flanging punch is the mold frame, and the first guide block and the second guide block are installed in the vertical direction in front of the mold frame.

5. The mold according to claim 4, characterized in that: The first guide block and the second guide block are higher than the mold frame by a certain height. The outside of the mold frame is the outer frame. The first positioning key and the second positioning key close to the front and rear sides of the mold frame are installed on the outer frame. Under the outer frame is the pad, under the pad is the lower template, and under the lower template is the pad. Each plate is fixed together with screws and pins to form a whole. At the same time, four hitting rods are installed between the pressure ring and the pad. The hitting rods pass through the pad and the lower template, and a certain length is exposed under the lower template.

6. The mold according to claim 5, characterized in that: During operation, the lower die is fixed as a whole on the lower platform surface of the stamping equipment through a pressing plate tool.

7. A method for forming a semi-spherical cover, characterized in that: The method comprises: Step 1: Install the upper die part of the mold on the upper platform of the punch press, and install the lower die part of the mold on the lower platform of the punch press, so that the upper and lower dies are fixed reliably; Step 2: Use the ejector device in the lower platform of the equipment and the ejector rod of the mold to lift the blank holder ring until the upper molding surface of the blank holder ring is higher than the convex mold surface, and prepare for material discharge; Step 3: Place the flat blank on the upper plane of the blank holder and align it; Step 4: Start the stamping equipment to press the upper die part downward. The C surface of the concave die in the upper die contacts the part first, and works together with the G surface of the blank holder to press the front, left and right surfaces of the upper surface of the blank. The blank in this area is the material outside the residual amount of the semi-spherical cover part of the product. Step 5: As the die continues to move downward, the concave mold surface B and the blank holder surface F work together to press the 10mm margin area on the edge of the semi-spherical cover part of the product. Since the material in this area is close to the forming area, the blank material in this area will flow; Step 6: As the concave die in the upper mold moves downward again, the semi-spherical surface D of the convex die in the blank holder contacts the blank, gradually forming a semi-spherical surface of the product; Step 7, the die continues to move downward until the die completely presses the blank holder to the lowest position, completing the forming process of the semi-spherical cover; at the same time, the flange punch completes the forming of the upward side flange of the semi-spherical cover part; Step 8: The upper mold moves upward to take out the part, completing the molding of the part.

8. The method according to claim 7, characterized in that The method further comprises: While step 7 is being carried out, the flanging punch located behind the punch and the blank holder lifts up the blank on the rear side.

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